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Hypotaurine protects against H 2 S‐induced oxidative stress and cell death in erythrocytes from an H 2 S‐tolerant marine worm
Author(s) -
Ortega Jessica A,
Ortega Jocelynn M,
Julian David
Publication year - 2008
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.22.1_supplement.758.40
Subject(s) - oxidative stress , hypotaurine , programmed cell death , chemistry , taurine , oxidative phosphorylation , biochemistry , microbiology and biotechnology , andrology , biology , apoptosis , medicine , amino acid
Many marine invertebrates adapted to H 2 S contain high concentrations of the organic osmolyte hypotaurine (H). In the presence of H 2 S, H is converted to thiotaurine (Th), and the Th:(H+Th) ratio is higher in animals from environments with higher H 2 S, suggesting that H can serve as a H 2 S buffer. However, H and possibly Th are antioxidants and therefore may also protect against free radicals produced by H 2 S oxidation. We used erythrocytes from the H 2 S‐tolerant marine polychaete Glycera dibranchiata to determine whether H reduces cell death and oxidative stress caused by H 2 S exposure in vitro. Greater than 90% of cells were killed by exposure to 0.3% H 2 S gas (based on calcein‐AM staining) but this death was decreased by 60%, 78%, and 83% with 0.5, 5.0 and 50 mM H, respectively (p<0.001 for each, n=8). Similar trends were observed at both higher and lower H 2 S concentrations (0.1, 1 and 3% H 2 S). Oxidative stress (based on H 2 DCFDA) was increased 67% by H 2 S (p<0.0001), but this increase was attenuated by H (p=0.0002). In contrast, H did not decrease the effect of H 2 O 2 (0.01–10 mM) on cell death (p=0.001) or oxidative stress (p=0.038), and H that was pre‐converted to Th did not reduce H 2 S‐induced cell death (p<0.0001). Therefore, hypotaurine protects against cell death and oxidative stress, although it remains unknown whether these effects are due to sulfide buffering or free radical scavenging.